Stitch-forming mechanism.



0,13. BROWN. STITCH FORMING MECHANISM.

APPLICATION FILED MAE. 4, 1910.

Patented Apr. 14, 1914.

2 SHEETS-SHEET 1.

I I n- WITNESSES:

INVENTOR ATTORNEY COLUMBIA PLANDGRAPH CO., WASHINGTON. D, c.

0. E. BROWN. STITCH FORMING MECHANISM.

APPLICATION FILED MAR. 4, 1910. 1,092,821. Patented Apr. 14, 1914.

2 SHEETS-SHEET 2.

IIVI/ENTOR 9; ATTORNEY COLUMBIA PLANOGRAFH CO.,WASNINGTON. D. c.

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OTIS E. BROWN, OF BROCKTON, MASSACHUSETTS, ASSIGNOR TO THE SINGER MANU FACTURING COMPANY, A CORPORATION OF NEW JERSEY.

STITCH-FORMING MECHANISM.

Specification of Letters Patent.

Patented Apr. 14, 19114.

Original application filed February 27, 1909, Serial No. 480,338. Divided. and this application filed March 4, 1910. Serial No. 547,243.

To all whom it may concern:

Be it known that I, OTIS E. BROWN, a citizen of the United States, residing at Brockton, in the county of Plymouth and State of Massachusetts, have invented certain new and useful Improvements in Stitch-Forming Mechanism, of which the following is a specification, reference being had therein to the accompanying drawings.

This application is a division of my application, filed February 27, 1909 (Patent No. 1,002,217, dated September 5, 1911), and the present invention relates to an improvement in stitch-forming mechanism designed more particularly for wax thread sewing machines, although not limited to such type of machines.

The invention has for its primary object to provide a simple and effective actuating mechanism for imparting reciprocatory movements to the needle; and to this end the actuating mechanism comprises a pit man-lever connected with an actuating crank and mounted upon a movable fulcrum having means for guiding it in a defined path, said pitman-lever. being connected with a crank-arm upon one end of a rock-shaft whose other end is connected with the me dle-bar carrying the needle. The oscillatory loop-taker preferably has an operative connection with said pitman-lever whereby the loop-taker receives operative movements in harmony with those of the needle to insure their proper coeperation in the production of stitches.

In the drawings, Figure 1 is a sectional rear side elevation of a machine embodying the present improvements, Fig. 2 a transverse section through the head of the bracket-arm, looking forwardly, Fig. 3 a front end view representing the forward portion of the machine, and Fig. 4 an elevation representing the needle and loop-taker actuating mechanism detached from the frame of the machine.

As represented in the drawings, the frame of the machine comprises the hollow standard 1 with cylindrical work-supporting arm or horn 2 and hollow overhanging bracketarm 3 terminating in the usual head 4. The needle 5 is mounted in the reciprocating needle-bar 6 journaled in the upper and lower bearings 7 of the laterally movable needleframe 8. The needle-bar carries the usual collar 9 with lateral stud 10 embraced by one end of the link 11 whose opposite end is connected with the stud 12 carried by the forwardly projecting crank-arm 13 of the needle-actuating rock-shaft 14 mounted in suitable bearings upon and longitudinally of the overhanging bracket-arm 3. At its rearward end, the rock-shaft 14 is provided with a depending crank-arm 15 connected by means of a link 16 to the upper end of a link-bar'17 whose lower end is provided with a strap 18 embracing the actuating crank 19 formed in the driving shaft 20 which is journaled within and transversely of the standard 1 parallel with the needle-actuatlng rock-shaft 14. As represented in the drawings, the rock-shaft 14 extends entirely across the upper end of the hollow standard 1 and has its rearward bearing at its extreme rearward end adjacent the crankarm 15.

Loosely mounted upon a shaft 21 journaled upon center screws 22 in the bearing lugs 23 extending rearwardly from the standard 1 is a sleeve 24 confined between thrust-collars 26 and constituting a member of a swinging yoke 27 which carries the conical center screws 28 entering the similarly apertured bosses 29 extending from the opposite faces of the link-bar 17. In following the rotary movements of the actuating crank 19 of the driving shaft, the linkbar 17 is thus adapted to move bodily upon the axis of oscillation of the yoke or radius.

bar 27, whereby the upper end of the linkbar 17 connected with the link 16 is moved in a substantially elliptical path with a nearly vertical major axis adjacent the rockshaft 14, and is confined to a range of movement permanently at one side of the axis of oscillation of the needleactuating rockshaft.

The several members of the mechanism are so proportioned and arranged that when the upper end of the link-bar is rising from its extreme lower and rearward position, a little below the position indicated in dotted lines in Fig. 4, its relation to the depending arm 15 of the rock-shaft is such that the needle is in its lowest position. As the linkbar rises to and slightly above the dottedline position of Fig. 4, the arm 15 is swung slightly forwardly to raise the needle sufficiently to throw out its loop for the shuttle, after which it moves upwardly and forwardly practically in an are described by the link 16, whereby the arm 15 is maintained stationary for a time sufficient to permit the distention of the needle-thread loop by the shuttle and the advance of the material under the feeding action, after which the approach of the upper end of the link-bar to the rock-shaft and its continued movement beneath the same causes the rapid movement of the crank-arm 15 to extreme forward position and consequent rise of the needle to its highest position. In the descent and backward movement of the upper end of the link-bar 17, the latter reaches its most advantageous relation with the crank arm 15 just as the needle is entering the goods resting upon the throat-plate 2" for a succeeding stitch, thus insuring the application of the full force of the mechanism at the time when the greatest load is imposed thereon.

The lower portion of the link-bar 17 is provided adjacent the strap 18 with a rearward offset or extension 17 X carrying a stud screw 30 embraced by one end of a pitman 31 whose opposite end embraces a similar stud-screw 32 carried by a lateral crank-arm 33 of a rocking sleeve 34 which is provided with a forked arm- 35 which embraces a roller-stud 36 carried by a crank-arm 87 upon the rearward end of the shuttle actuating rock-shaft 38 which is journaled in bearings 39 within the cylinder arm 2 and carries at its forward end the shuttle-driver 40, The shuttle 41 is of the wellknown Singer oscillating type, provided with the barrel thread-case 42 and fitted to oscillate within a race 43 at the forward end of the cylinder-arm 2, the throat 44 and heel 45 of the shuttle being alternately engaged by the arms of the shuttle-driver in a wellknown manner. By the particular arrangement of the link connection 31 with the link-bar 17 described above, the shuttle movements, are timed, as before recited, so as to cooperate with the needle in the manipulation of the upper thread so as to seize and distend the needle-thread loops while the needle-eye is beneath the work, thus avoiding any undue strain upon the thread in the loop-seizing and casting operations which would be produced in case the rise of the needle were hastened or the action of the shuttle upon the needle-thread were delayed.

'Mounted loosely upon the rock-shaft 14 between thethrust-collars 46 is a rocking sleeve 47 having two rearwardly projecting and angularly disposed arms 48 and 49, the former of which is connected by means of the link 50 with the upper end of the linkbar 17 by means of the stud-screw 51 to which the link 16 is connected. The crankarm 49 of the sleeve 47 is connected by means of a bent link 52 with a crank-arm 53 fixed upon the take-up rock-shaft 54 mounted in suitable bearings 55 upon the bracket-arm 8. Therock-shaft 54 is provided intermediate said bearings with an offset portion 56 between which and its ex-- treme forward end it is formed with an axial thread-aperture 57.

Upon the forward end of the rock-shaft 54 is fixed the hub 58 of the take-up arm or lever 59 carrying the grooved tension-wheel 60 one side of which is disposed substantially in'alinement with the thread aperture of the ta.keup rock-shaft, the tension-wheel being journaled upon the pin 61 fitted to a suitable transverse bearing of the take-up arm and having a head 62 normally rest ing upon the outer face of the take-up wheel,

a spring 6.3 being interposed between the bearing in the arm 59 and the adjusting nut 64 applied to the threaded opposite end of the bearing pin, whereby the tension-wheel 60 is normally subjected to a slight frictional drag which is increased at such times as the vibration of the take-up arm carries the head 62 of the bearing pin 61 into engagement with the spring-arm 65 secured upon the split supporting pin 66 mounted in the bracket-arm.

The take-up arm 59 carries at its outer end the thread wheel 67 mounted upon the stud-screw 68 and intermediate its ends a V similarly grooved thread-wheel 69 mounted upon the stud-screw 70, each of said thread-i wheels being embraced between the expanded adjacent ends of theguard loops 71 and 72 bracket-piece 7 8 secured to the needle-frame 8 by the fastening screw 79, and thence through the guide-strap 80 to the eye of the needle 5. Between the guide-roll 76 and the stud-screws 77 the thread is confined against disarrangement by passing through the guard-loops 71, 75 and 72.

The take-up arm assumes its lowest position just after the point of the shuttle has seized the needle-thread loop, and startsits rising 'mo-vement Without any immediate effect upon the thread extending from the roll 76 to the guiding stud-screws '77 until the shuttle has reached'itsmost advanced position and the eye of theneedle has risen above the work, when the grooved rollers 67 and 69 engage the thread below and upon opposite sides of the stationary guide-roller supporting pin 74, and the continued rise of the take-up arm causes the bending of the thread around the stationary roller for taking up the slack needle-thread and setting the stitch, the latter being effected as the take-up arm and the needle reach their high est posit-ions. As the take-up arm descends, slack needle-thread is given up to permit the seizure and expansion of the needle-thread loop by the shuttle for the succeeding stitch.

The driving shaft is provided, adjacentthe crank 19, with a feed-actuating cam 81, which is embraced by a yoke 82 formed at the lower end of a rock-lever 83 whose upper end is pivotally connected by means of the screw-stud 84: with the depending crank-arm 85 at the rearward end of a rock-shaft 86 mounted upon the front side of the bracketarm 3 and having fixed upon its forward end a. depending arm or lever 87. The arm 87 is pivotally connected by means of a pin 88 with a forwardly extending lug 89 of the needle-frame 8 whose rearward edge has a lug 90 carrying a stud 91 sustaining a slideblock 92 which movesin the stationary segmental slideway 93 having a curvature corresponding with the path of circular movement of the pivotal pin 88 by which the opposite edge of the needle-frame is supported, to insure the parallelism of the ncedleframe in the different lateral positions which it assumes under the action of the feed-cam 81.

The stitch-regulating lever 94 has one end integral with the rock-shaft 21 and its other end projects forwardly therefrom, while its intermediate portion carries the fulcrumstud 95 entering a segmental recess 96 of the lever 83 for which it affords a movable fulcrum. The position of the lever 94': obviously determines the fulcrum point of the rocklever 83 by means of which the range of lateral movement of the needle in the line of seam is determined.

The feed-actuating cam 81 is so shaped and secured upon its supporting shaft that it imparts to the needle, through the described connections, a lateral feeding movement during the dwell of the needle in each reciprocation and while the needle-thread loop is being distended and cast about the lower thread by the shuttle. This relative timing of the needle and shuttle actuations is important, because the advance of the work should be delayed until the seizure of the needle-thread loop by the shuttle to insure certainty of action of the latter, and should terminate before the point of the needle emerges from the work so as to utilize each entire feeding movement of the needle without injury to the face of the work by the emerging point of the needle. The needle reciprocating mechanism herein shown and described is particularly adapted to produce adwell of the vertical movement of the needle at such time and of such duration as to cooperate with the shuttle mechanism and the feeding means to accomplish the described result.

I-Iaving thus set forth the nature of the invention, what I claim herein is 1. In a sewing machine, the combination with a driving shaft a throat-plate, an endwiseand sidewise movable eyed needle, and a loop-taker cooperating with said needle in the production of stitches, of actuating means connected with the driving shaft for imparting to the needle endwise reciprocating movements with a dwell while the needle is between extreme positions and while the needle-eye is at that side of the throat-plate adjacent the loop-taker, means operatively connected with said needle-actuating means for actuating the loop-taker to seize and distend a needle-thread loop before the end of the dwell'of said needle, and means for imparting to the needle sidewise work-feeding movements during said dwell in its reciprocatory movements.

2. I11 a sewing machine, the combination with the main-shaft provided with a crank, of a pitman-lever connected with said crank, a movable fulcrum for said pitman-lever with means for guiding it in a defined path, a rock-shaft, a crank-arm thereon, a connection intermediate said crank-arm and pitman-lever, a needle-bar, a needle carried thereby, an operative connection intermediate said needle-bar and rock-shaft, a looptaker, and means connected with and actuated through said pitman-lever independently of its fulcrum-guiding means for actuating said loop-taker.

3. In a sewing machine, the combination with the main-shaft provided with a crank, of a pitman-lever connected with said crank and carrying a pivotal stud offset from such point of connection, a movable fulcrum for said pitman-lever with means for guiding it in a defined path, a rock-shaft, a crank-arm thereon, a connection intermediate said crank-arm and pitman-lever, a needle-bar, a needle carried thereby, an operative connection intermediate said needle-bar and rockshaft, a loop-taker, an actuating rockshaft for the same provided with a crankarm carrying a stud, a pluralarmed rocker having one arm slotted to embrace said stud, and a connection between a second arm of said rocker and the pivotal stud upon said pitman-lever.

4'. In a sewing machine, the combination with the main-shaft provided with a crank, of a pitman-lever connected with said crank, a movable fulcrum for said pitman-lever with means for guiding it in a defined path, a rock-shaft, a crank-arm thereon, a second rock-shaft, a crank-arm thereon, independent connections between said pitman-lever and the crank-arm of said rock-shafts, a needle-bar, a needle carried thereby, an operative connection intermediate said needlebar and the first-named rock-shaft, a takeup arm mounted upon the second-named r0ok-shaft, a loop-taker, and means for actuating said loop t-aker.

5. In a sewing machine, the combination with the main-shaft provided with a crank, of a pitman-lever connected with said crank, a movable fulcrum for said pitman-lever with means for guiding it in a defined path, arock-shaft, a crank-arm thereon, a second rock-shaft, a crank-arm thereon, an intermediate rocker, a pitman connection intermediate said rocker and the crank-arm of the second-named rock-shaft, independent connections between said pitmanlever and the crank-arm of the first-named rock-shaft and between said pit-man-lever and said intermediate rocker, a needle-bar, a needle carried thereby, an operative connection intermediate said needle-bar and the first-named rockshaft, a take-up arm mounted upon the sec 011d named rock shaft, a loop taker, and means for actuating said loop-taker.

6. In a sewing machine, the combination with the main-shaft provided with a crank, of a pitman-lever connected with said crank, a movable fulcrum for said pitman-lever with means for guiding it in a defined path, a needle actuating rock shaft, a take up rock-shaft, a crank-arm upon each of said rock-shafts, independent connections between said crank-arms and the pitman-lever, a needle-bar, a needle carried thereby, an operative connection intermediate said needlebar and needle-actuating rock-shaft, a takeup arm mounted upon the take-up rockshaft, a loop-taker, and means for actuating said loop-taker.

7. In a sewing machine, the combination with a driving shaft, a throat-plate, an endwise and sidewise movable needle, and a loop-taker cooperating with said needle in the production of stitches, of actuating means operated by said shaft for imparting to the needle endwise reciprocating movements with a dwell while the needle is between extreme positions and while the needle-eye is at that side of the throat-plate adjacent the loop-taker, means having direct operative connection with said needleactuating means, for actuating the looptaker to seize and distend a needle-thread loop before the end of the dwell of said needle, and means for imparting to the needle sidew i'se work-feeding movements during said dwell in its reciprocatory movements.

8. In a sewing machine, the combination with the main-shaft, of a pitman-lever connected to said shaft, a needle, a loop-taker cooperating with said needle in the production of stitches, a take-up arm, rock-shafts and connect-ions adapted to actuate said needle, loop-taker, and take-up arm, means for imparting to the needle sidewise workfeeding movements, and means dlre'ctly connecting said rock-shafts and pitman-lever OTIS n. BROWN.

Witnesses HENRY J. MILLER, H. A. KORNEMANN, Jr;

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. 

